In a dozen Twitter missives over the past three days, President Trump has accused Democrats of failing to protect young undocumented immigrants, criticized Mexico for its role in illegal immigration to the United States and warned of “caravans” of people headed toward the southern border.

At least half of his statements were inaccurate. Here’s a fact-check.

Mr. Trump warned that new immigrants would take advantage of DACA, and said that Democrats were responsible for the program’s demise.

This is not possible in the first case and false in the second.

These big flows of people are all trying to take advantage of DACA. They want in on the act!

In several tweets, Mr. Trump referred to “caravans” of immigrants headed toward the United States’ southern border. Buzzfeed has reported that hundreds of Central Americans are walking en masse through Mexico, staying together for protection from cartels and immigration authorities. Organizers estimated that up to 10 to 15 percent of the migrants would seek asylum at the United States border.

But to qualify for DACA, or Deferred Action for Childhood Arrivals, the immigrants would have had to have been living in the United States since 2007. Furthermore, in September Mr. Trump rescinded the program, which shielded immigrants who arrived in the United States illegally as children from deportation.

Though the program’s fate is tied up in court, American immigration officials are not accepting new applications.

A White House official said Mr. Trump was referring to a bipartisan Senate bill that would have extended applicants’ eligibility to 2012 from 2007. It also directed the Department of Homeland Security to prioritize deporting criminals.

The bill failed in the Republican-controlled Senate. But even if it had become law, immigrants entering the United States today would still not qualify.

Several states won injunctions in January and February requiring the federal government to accept applications from current DACA recipients to renew their resident status. On Tuesday, citing data from United States Citizenship and Immigration Services, Attorney General Xavier Becerra of California estimated that at least 30,000 of the so-called Dreamers have been able to renew their DACA status since January.

It’s also misleading to claim that the Democrats did not act to renew DACA, as The New York Times reported last month:

Democratic leaders have rejected Mr. Trump’s demand to pair the program with funding for a border wall, but that is not nearly the same as not wanting a legislative solution at all.

In February, Representative Nancy Pelosi of California, the House Democratic leader, delivered an eight-hour speech about the plight of the young undocumented immigrants known as Dreamers. The Congressional Hispanic Caucus, in a letter dated Feb. 28, said Mr. Trump had “thwarted every bipartisan, narrow agreement that seeks to provide relief for Dreamers” and listed a few examples.

He accused Mexico of doing nothing to address illegal immigration but said the country had “strong border laws.”

These tweets contradict each other and require context.

Mr. Trump first chastised Mexico for not preventing Central American migrants from reaching the United States. But a day later, he praised Mexico for its “strong border laws.”

Though some advocacy groups and researchers have found that Mexico’s approach to curbing illegal immigration is ineffective, the country is not doing “nothing.”

The Mexican government adopted its Programa Frontera Sur, or southern border program, in 2014 to protect migrants and the country’s ports of entry. Assessments from Rice University and the Washington Office on Latin America found that Mexico has had success detaining and deporting migrants, but failed to protect migrant rights or adopt a comprehensive strategy for long-term solutions.

More broadly, Mr. Trump’s characterization of Nafta as a “cash cow” for Mexico is wrong. Most research has found that Nafta has had a positive, but modest, net impact on Mexico’s economy.

It is true that the pact helped increase Mexico’s trade globally. Since Nafta went into effect in 1994, Mexico’s foreign direct investment has drastically increased, its manufacturing sector has become more productive, and it has generally widened trade with the rest of the world.

The president excoriated the so-called catch-and-release immigration enforcement policy as an example of “ridiculous liberal (Democrat) laws.”

This is false.

“Catch and release” refers to the practice of paroling detained immigrants as they wait for courts to determine whether they should be deported. The Supreme Court has ruled that unauthorized immigrants who have been ordered to be deported generally cannot be detained for more than six months. Women and children who are held together must be released within 21 days under a separate 2016 federal court ruling that minors cannot be held for extended periods.

There is also not enough detention space to house captured immigrants. In the 2017 fiscal year, for example, Immigration and Customs Enforcement detained a daily average of about 38,000 people, but had only 34,000 beds available for the majority of the year. (Congress funded 5,300 additional beds in May, with four months left in the 2017 fiscal year.)

In October, Attorney General Jeff Sessions said a backlog of cases was contributing to the release of immigrants. “There is so many people claiming and being entitled to hearings that we don’t have the ability to provide those hearings, and they’re being released into the community and they’re not coming back for their hearings,” he said.

Additionally, the government already turns away far more people who are stopped at or near the border — and are not subjected to lengthy court proceedings — than unauthorized immigrants who are caught within the United States.

Asked to explain Mr. Trump’s tweet, the White House provided a February fact sheet from the Department of Homeland Security that focused mostly on unaccompanied immigrant children. It concluded that only 3.5 percent of the unaccompanied minors were eventually deported, and blamed a 1997 court settlement and a 2008 law for creating “legal loopholes” permitting their release from detention.

The 1997 case dates to the Reagan administration. It was settled under the Clinton administration to ensure humane treatment and care of unaccompanied minors when their cases are processed by the federal government. Laws passed in 2002 and 2008, under President George W. Bush, then divided the responsibilities for apprehension and care of unaccompanied children among federal agencies.

Correction:

An earlier version of this article misstated a Supreme Court ruling on immigrant detention. The court ruled that unauthorized immigrants who have been ordered to be deported generally cannot be detained for more than six months, not that they can never be detained for more than six months.

Linda Qiu is a fact-check reporter, based in Washington. She came to The Times in 2017 from the fact-checking service PolitiFact. @ylindaqiu

A version of this article appears in print on , on Page A19 of the New York edition with the headline: Immigration Policy: A Rant That Misleads. Order Reprints | Today’s Paper | Subscribe